Targets or devices can be used for authentication, tracking, anti-counterfeiting, inspection of products, or other applications in which intentionally embedded information can later be read and used for one or more purposes. The targets can be printed on, or attached to, the packaging for products. The targets or devices typically contain information encoded into the device. The information may be encoded into the device using a pattern of black and white, grayscale, or color features, patches or lines. One example is a bar code, which can be used for point-of-sale, product tracking and steganographic data carrying simultaneously.
Color based targets or devices provide additional complexity and data density as compared to grayscale or black and white targets. This increase is largely due to the increase in total possible combinations which are feasible as deterrents are switched from black and white to grayscale to color. For a single mark or feature, black and white provides 2 possible choices, 8-bit grayscale provides 28 possible choices, and 24-bit color provides 224 possible choices. As the number of marks per device increase, the total possible combinations for a color based device far exceeds the total possible combinations for a black and white or grayscale device. This makes the color target or devices more effective and more informational-dense.
The trade-off in moving from black and white or grayscale to color is that the computational complexity in evaluating a mark or feature in a device directly increases with the possible combinations. This computation complexity occurs in several areas including, but not limited to, increased, data storage, memory usage, and selection of image processing algorithms used to correctly identify and decode, a mark or feature. In addition, scanning a device in color may be slower than scanning the same device in black and white or grayscale.